Miguel Rosa Duque shows a round-trip of using Maya with Human IK to ipiSoft marker-less motion capture and then taking that information back to Maya and using it for a character in this 5 part video showing his process.

iPi Desktop Motion Capture is a markerless motion capture technology that puts motion capture at the desktop level. You can record a video using 1 or 2 MS Kinects, webcams or digital cameras and have it converted to 3D animation on your computer.